Researchers have used an experimental drug to help obese monkeys lose weight — and it could work for humans too.

The medication, Adipotide, works by finding and sticking to proteins on the surface of blood vessels that feed white fat cells, and then releasing a synthetic molecule that kills those cells.

The study with monkeys found that those treated with Adipotide lost an average of 38.7 percent of their total body fat, more than twice the amount lost by others. The main side effects were increased urine output and slight dehydration, both reversible and varied by dose.

The drug will next be tested in obese human patients being treated for prostate cancer.

In a statement, researcher Dr. Wadih Arap said, “Obesity is a major risk factor for developing cancer, roughly the equivalent of tobacco use, and both are potentially reversible … The question is, will their prostate cancer become better if we can reduce their body weight and the associated health risks.”